Method of designing orthopedic plates and plates made in accordance with the method

ABSTRACT

The present invention relates to a method of designing an orthopedic implant in which a plurality of samples of the bone are selected and a CT scan of each of the samples of the bone is taken so that the data from the CT scan can be used to generate a 3D graphical solid body model of each of the sample of the bone. The 3D graphical models are placed into a category of one or more of average, small, and large, and the center of mass and an X, Y and Z plane for each model is determined. The 3D graphical models for one category is assembled and aligned at the center of mass to create a categorized composite 3D graphical solid body model of the bone. The categorized composite 3D graphical model is sectioned at a specified interval to create a lofted contoured surface of a selected thickness which is cut to create a categorized implant profile. The categorized implant profile is graphically fit on the categorized composite 3D graphical model and on the 3D graphical model of each of the sample of the bone in a category to check for conformity to the surface of the bone. The categorized implant profile is used to create a design of the implant.

FIELD OF THE INVENTION

The invention relates to a method of designing site specific orthopedicplates, and more particularly to a method of designing an orthopedicplate that mimics the topography of a bone site and which is intendedfor fixation to a specific part of anatomy for stabilization of acharacteristic type of fracture or osteotomy.

BACKGROUND OF THE INVENTION

The paradigm for prior art orthopedic plates has involved drawing animage of the plate to suit a general outline of a site where the platewas intended to be implanted. Thus, the plate began its conception as atwo dimensional representation. The final manifestation was crafted frommetal and often had no, or very crude profiling in the Z direction. Asthis corresponded poorly with the surface of the bone that it wasdesigned to fit, the plate was made relatively thin to allow the surgeonto contour the plate before implantation. In addition, the plate wasmade somewhat thin so that it could be fixed in place on the bone andthat the bone itself would provide the basis of the final sculpting.This paradigm presents several problems for the attending surgeon.First, the surfaces of bone are far from flat, and the smaller the bone,the greater the relative contouring that the surgeon had to accomplishduring the surgery. Second, while intact cadaveric bone can provide abasis for contouring a flexible plate, this idea is less successful withbone that has been fragmented, and the worse the break, the moredifficult the reconstruction. The present invention provides the meansto design orthopedic plates that can be used as the scaffolding forreconstruction of broken or deformed bone or for bones otherwiserequiring orthopedic attention. The means of accomplishing the design ofsuch a plate is the use of imaging studies of human anatomical samplesto construct a generalized three dimensional solid model from which oneor more computer models or resin samples can be made and which forms thebasis for the three dimensional design of a corresponding orthopedicplate which is easily subject to subsequent development and designreview.

In particular, the present invention uses a high-resolution model of thedistal radius based on imaging studies of human anatomical samples.Samples of 16 cadaveric distal radii were harvested and high-resolutionCT scans of the samples were collected and the CT data were converted tosolid-part 3D models. Measurements from the cadaveric samples, CT sliceimages, and 3D solid part models were compared to verify the accuracy ofthe models. Individual models were then overlaid to create three sizesof composite models of the distal radius. In addition, simple plasticmodels of the samples were created using a 2-step casting process. Thisprovided a physical correlation to the digital model for more accuratelyfitting the prototype plates. The current invention provides theadditional advantage that the digital model created can be used forspecific description of the distal radial anatomy, as well as the designand testing of fracture fixation hardware and surgical approaches andtechniques since the resin castings that are created arecharacteristically hard and are difficult to drill or otherwisephysically test.

The process described here may also be used to create similar models ofother bony structures for similar end uses, including specifically smallbones (i.e., below the elbow or knee, or the clavicle) and joints suchas the calcaneus, the tarsals, and metatarsals, the carpals andmetacarpals, the tibia, the fibula, the clavicles; long bones such asthe humerus, femur, and the ulna; the vertebrae, and the pelvis and thebones of the skull.

Fractures of the distal radius are among the most common seen byorthopedic surgeons, with estimates of annual incidence ranging from 9per 10,000 to as high as 120 per 10,000 in different populations.However, while several authors have utilized CT of the distal radius forspecific diagnoses, no high-resolution model of the distal radiusarticular surface, epiphysis, and metaphysis based on data acquired fromhuman materials has been reported in the literature.

In order to construct an accurate model of the distal radius,high-resolution, minimal-noise CT scans of distal radii were acquiredfrom an immediately available selection of sixteen cadaver samples. Thedata from the CT scans were then used to create a composite digitalmodel of the distal radius, which represents a composite of the modelsof the individual bones. This model is used in accordance with thepresent invention to describe in depth the typical geometry of thedistal radius for design of orthopedic hardware and for injurymanagement including surgical technique. Subsequently, the models drawnin cross section at a defined interval and a plate is constructed in aprocess termed “lofting” in which a cross section of plate is added atthe surface of the bone (assuming to begin with that the section isrectilinear) and the plate sections are aggregated to construct a plateform which blankets the graphical bone model at its surface and which issubsequently formed to a outline that is appropriate to a particularindication. Alternatively, the outline can be selected first and theplate form can be cut in the outline shape when it is designed. In anycase once the form is designed and the outline is selected, there is aplate shape design which can be used with the bone model to placefixation means, which can include all of the varieties of fixation,including but not limited to bone screws and pegs, including locking andunlocking varieties of each, K wires, wires, tensioning devices, boneanchors and adhesive. Once fixation means are added, there is plateprototype design that can be studied through computer analysis toaccommodate various considerations, such as typical fractures or bonedeformities, complications, problems of approach including soft tissueinvolvement, and loading that the implant or plate typically withstands.This easily enables the involvement of medical experts who can reviewelectronically transmitted proposals and can comments on considerationssuch as the ability to capture typical fragments, fixation concerns suchas impingement of fixation means on the construct or interference withsoft tissue, and other issues involving ease of surgical approach andimplantation. Further, it is of great assistance to make physical-modelsof plate and bone to allow medical advisors to play with placing theplate on the bone and suggest further advantageous adaptations. Whilethe resin that is often used for modeling is too hard to allow for asimulation of implantation in bone, a resin model can be used to make afemale mold that can be used to make a further model of artificial boneso that the medical personnel can play with the entirebone/plate/fixation construct to make additional suggestions that areincorporated into the final plate design. Thus, the method of thepresent invention allows far more intensive study of many aspects of theplate/bone/fixation construct enabling the possibility of better fit,ease of surgical use, better standardization for the relevantpopulation, and better fixation and reduction eliminating possiblecauses of future complications, including misalignment and attendantjoint pain and malfunction, and arthritis.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the invention, digital information is collected whichcorresponds to a sample population for a particular anatomical site. Theinformation can be generated from known imaging techniques including CTscans, MRI or radiographic techniques. The sample may include cadaversor live specimens. The group may be defined to include particularcharacteristics, for example, a geriatric or pediatric population, or ageneralized sample of the relevant population for a location. Inparticular, a representative sample of from about 4 to about 50, andmore preferably from about 6 to about 30 and most preferably from about10 to about 20 samples of a desired bone are harvested from cadavers.The cadavers are selected to give a representative sample as tovariations in size. Thus, the cadavers used are of both genders, and ofvarying ages. The soft tissue is cleaned from the bone, attendant jointsare disarticulated and the bone samples are transected. The samples areallowed to desiccate and grouped into basic categories of size. Highresolution CT scans are taken as an axial section of the bone, beginningat the diaphysis and proceeding distally. Verification of the CT imagesis performed by comparing caliper measurements of the bone withcorresponding measurements of the CT scans. All of the images are savedas DICOM files for future creation of three dimensional models and forcreation of solid models. A representative model is confirmed bycomparing measurements from the model with those previously taken fromradius samples and from the CT scans. With the completed solid-partmodels grouped by size as previously described, the center of mass ofeach model is determined and X, Y, and Z planes defined for eachindividual model. The models for the six medium-sized samples are thenaligned at their respective centers of mass and overlaid to produce acomposite model. Composite models for the small- and large-sized groupsare created in the same fashion and hard plastic models are created andused to make negative casts that permit creation of additional models.The plates are designed using a CAD program by overlaying a layer of adetermined thickness on a surface of the 3-D model of the bone. Plasticprototypes are made from the projected CAD models and fitted to theplastic models of the bone. Input is solicited from engineers andsurgeons and the initial implant design is adjusted to fit theindication as well as to accommodate the surgery so as to produce afinal design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an orthopedic plate designed in accordance withthe invention;

FIG. 2 is a side view of the plate of FIG. 1;

FIG. 3 is a first end view of the plate of FIG. 1;

FIG. 4 is a second end view from the plate of FIG. 1;

FIG. 5 is a view of the plate of FIG. 1 on a bone with pegs or screws;

FIG. 6( a) is a representation of the distal portion of a radial boneand

FIG. 6( b) is a three dimensional graphic representation of the bone;

FIGS. 7 (a)-7(e) are three dimensional graphical representations of thedistal portions of individual radial bones;

FIGS. 8 (a)-8(e) are three dimensional graphical representations of thevolar surfaces of distal portions of individual radial bones;

FIG. 9( a) is an illustration of the three dimensional representation ofthe composite model of the distal portion of a radial bone viewed at thevolar surface, and FIG. 9( b) is the same model viewed from the distalarticular surfaces;

FIG. 10( a) is an illustration of the three dimensional representationof the composite model of the distal portion of a radial bone in amedial/volar view, and FIG. 10( b illustrates a corresponding platedesign;

FIG. 11( a) and 11(b) is an illustration of an initial design of theplate with pegs and a drill guide, taken from the top and from the side;

FIG. 12( a) illustrates a revised plate design viewed from the top onthe distal portion of a radial bone being subjected to a load, and FIG.12( b) illustrates the same plate design viewed from the lateral side,while FIG. 12( c) illustrates the same plate design viewed from themetacarpal articular side; and

FIG. 13( a) is a further iteration of a plate design showing a revisionto accommodate variable locking pegs and FIG. 13( b) is a view of thefurther iteration showing the placement and angulation of the fixationmeans.

DETAILED DESCRIPTION OF THE INVENTION

In order to begin the design process of the present invention, digitalinformation is collected for a particular anatomical site. Theinformation can be generated from known imaging techniques including CTscans, MRI or radiographic techniques. The sample may include cadaversor live specimens. The sample group may be defined to include particularcharacteristics, for example, a geriatric or pediatric population, or ageneralized sample of the relevant population for a location. Inparticular, a representative sample of from about 4 to about 50, andmore preferably from about 6 to about 30 and most preferably from about10 to about 20 samples are collected. In this instance, a sample ofsixteen right distal radius specimens were harvested from preservedcadavers at Washington University School of Medicine. Six male cadaversand 10 female cadavers were used, ranging in age at time of death from61 to 98 (Table 1). All soft tissue was stripped from the bone samplesbeginning at middiaphysis and working distally. The distal radioulnarand radiocarpal joints were disarticulated, and the radius wastransected 10 cm proximal to the tip of the radial styloid. Allremaining soft tissue was removed from the samples, and they were setaside to desiccate for three weeks before analysis. These samples werecategorized, meaning that the specimens were grouped into small (5),medium (6), and large (5) based on an estimate of distal width. Itshould be understood that other categories could be used depending onthe typical variations in shape and size of the anatomical location. Forexample, for some bones, the samples could be grouped into long, medium,and short, or into wide and narrow bones.

High-resolution CT images of the samples were obtained individually on a64-detector spiral CT [Siemens]. The slice thickness was set to 0.4 mm.Samples were scanned with each CT slice as an axial section of the bone,beginning at the diaphysis and proceeding distally. Verification of theCT images was performed by comparing caliper measurements of the widestpoint of the distal radius samples with corresponding measurements fromthe CT scans (Table 2). All images were saved as DICOM files in order toallow creation of 3D reconstructions and conversion to solid-partdigital models.

The data from the CT scans was inputted into a software package thatreads output from a CT scan and generates a 3D model from thecross-sections given the image spacing. It is highly preferable that themodel created can be read by common 3D CAD programs, such as forexample, the program presently sold by SolidWorks, Corp. as“SolidWorks”. In particular, the files from the CT sans were convertedfrom the original file extension to a .vip file that could be convertedby SolidWorks to a SLDPRT file or solid part file. The file for eachradius that was scanned was converted to a solid part file and used tocreate a three dimensional graphical solid body model for each radiusbone. The models were examined and it was decided how many categories touse for categorization of the individual variations. In this instance,there is sufficient variation, in particular in taking into regardgender variations, to account for a small, medium and large category ofradius bone. Thus, the models were “categorized”, meaning that they wereseparated as is appropriate to account for variations in the bone shapesand sizes. For bones, other than the distal radius, it may only benecessary to separate samples into a small and large category, and forother bones one size and shape of plate may serve for all expectedindividuals in a given population. Further, the bones studied were allright radius plates (and the left plates were designed as mirror imagesof the right plates), but it is understood that the invention couldeasily, and perhaps preferably, include samples scanned for both theright and the left side.

Beginning with the medium category, the center of mass was determinedfor each graphical model, and subsequently, X, Y, and Z planes werecreated for the models. All of the bones in a category were placed in anassembly in a single model and aligned at their center of mass to createa composite graphical model for that category. Drawings were created ofthe bones showing their critical dimensions: i.e. overall length, distalwidth, radial styloid location, volar tilt angle, and any otherdimensions, or landmarks that might be desired during the designprocess. These dimensions were used to determine the sizes of platesrequired, the shape, (i.e., the footprint in the X, Y, direction) andthe profile (ie., the topography of the plate as viewed in the Zdirection).

A representative model was confirmed by comparing measurements from themodel with those previously taken from radius samples and from the CTscans (Table 2). With the completed solid-part models grouped by size aspreviously described, the center of mass of each model was determinedand X, Y, and Z planes defined for each individual model. The models forthe six medium-sized samples were then aligned at their respectivecenters of mass and overlaid to produce a composite model or assembly.Composite models for the small- and large-sized groups were created inthe same fashion.

The medium composite graphical model was subsequently sectioned at apredefined distance (i.e. about every 0.5 to about every 2 millimeter,and more preferably about every 0.75 to about every 1.25 millimeter, ormore precisely about every 1 millimeter). Cross sections of thecomposite bone were drawn to determine planes. A lofted surface with adefined plate thickness for each individual section was created byconnecting cross sectional data points to a cross-section on a plane aspecified distance. The plate profile was cut into the lofted contouredsurface to create a graphical plate form that corresponds to thetopography of the bone. The form was fit to a determined outline toproduce a plate design. This plate design was graphically placed on thecomposite medium bone model as well as each of the individual graphicalmodels to check for conformity to the bone surface. Adjustments weremade as desired. The fixation holes in the plates were placed using thegraphical three dimensional models along with data relating to commonfractures and indication and to the need for fixation and reduction. Thelocation and angles of the fixation holes were subsequently checked bygraphically modeling the plate/bone/screw construct for the compositeand for individual graphical models.

Further in accordance with the invention, three-dimensional solid-partmodels were created for each individual radius, for the categorizedcomposites and for the plate design. These models were SLA(sterolithography rapid prototyping) models made from PMMA resin andwere created on a 3D plastic plotter. Preferably, hard plastic modelswere created using polymethylmethacrylate (PMMA). Negative casts weremade of the original radius samples in Alginate Impression Material(ADC, Milford, Del.), with an emphasis on careful recreation of thedistal end of each sample. These molds were then immediately used tomake positive casts of the radii using Coralite Duz-All Self CureAcrylic (Coralite Dental Products, Skokie, Ill.). The models wereallowed to harden and cure; irregularities that arose during the castingprocess were removed by use of a surgical rongeur or premmer andattachments.

The plate SLA models were placed on the radius models as a verificationof the contour conformity and hole location. The bones and the proposed(i.e., prototype) plate designs were supplied to advisory board surgeonsfor review during the design process.

Initial CT scans of our sixteen distal radius samples yieldedhigh-resolution models of each of these samples. These scans were thenconverted to sixteen individual solid-part models of the samples.Verification of these models by comparison of representativemeasurements from the sample radii, the CT slice images, and the 3Dmodels assures that the model is an accurate representation of thephysical anatomy. After classifying these individual models into sizegroups based on the specific criteria of maximal distal width, highresolution models representing composites of each group were created byoverlaying the individual models. This composite model is a highresolution representation of the average geometry and anatomy of thedistal radius in a selected sample of cadavers.

Additionally, the present invention provides the simple andcost-effective production of hard-plastic models to serve as correlatesto the digital models. These models play an important role not only inproviding a tactile correlate to the radiographic data, but also allowfor physical testing of reconstruction methods and hardware on exactreproductions of the sample bones. In addition, while the resin modelsare too hard to provide correlation to bone, they can be used to createfemale molds that can be used to create models from artificial bone toallow prototype plates to be attached using the proposed fixation meansto further the development of the final plate design.

The method of the invention contemplates the use of a more random samplepopulation for example as to age, gender, geographic location, and forleft and right handed individuals in order to accommodate dominant andnon-dominant handedness in the bone samples and in order to ensure thatthe model can be more widely extrapolated.

The computer image of the present invention presents several advantages.First, high resolution reconstructions for each of the each of theindividual bones in the sample have been generated and measurement ofnumerous variables for each of these samples can be used in adescription of the distal radial geometry. Second, the model reported isa direct three-dimensional composite of several samples and thus has thebenefit of being somewhat “averaged” across the sample populationwithout the limitations of a model created entirely from averagedmeasurements. Third, the composite model created is used for purposesbeyond a geometric description of the distal radius; potential usesinclude design of fixation hardware, prosthesis design, and virtualmanipulation to test surgical approaches and techniques. Finally, theprocess described here for the creation of both digital and plasticmodels is in no way limited to application for the distal radius; thesetechniques can be used for creation of models of many other structureswith similar end uses.

The design methodology of the present invention presents the followingadvantages: it results in an implant, such as a plate or otherstabilization or fixation construct, that is contoured to fit theindication; it enables the designer to strategically place fixationholes and angles; it provides a means for verification of implant fit;it provides the ability to refine the plate design through numerousiterations on the basis of the initial analysis and modeling and also todesign a system of sizes and shapes that best serve the commonvariations in the population; the graphical and solid models provide anincredible amount of technical information that can be incorporated indesign as needed; and it provides models that are easily available foruse in finite element analysis (FEA).

TABLE 1 Cadaver Information Sample Number Sex Age 1 M 78 2 M 91 3 F 77 4F 95 5 F 87 6 M 61 7 F 98 8 M 78 9 F 85 10 M 83 11 M 89 12 F 88 13 F 9414 F 84 15 F 85 16 F 73

TABLE 2 Measurements of Radius Sample, CT slices, and 3D Model Radius-Distal CT Slice- Distal 3D Model- Distal Sample Width (mm) Width (mm)Width (mm)  1 34.1 34.5  2 31.8 31.4  3 29.4 29.3 29.5  4 31.8 30.7  534.1 34.2  6 32.5 32.1  7 31.8 32.1  8 29.4 29.3  9 32.5 31.4 10 33.333.5 11 33.3 33.5 12 30.2 29.3 13 32.5 32.8 14 31.8 32.1 15 32.5 32.1 1632.5 32.8 Mean 32.1 31.9 standard Dev. 1.4 1.7

Radius width was measured using calipers at the widest point on thedistal radius. CT slice width was measured as the width of the widestslice acquired within the distal radius. Model width was measured usingthe “measure” tool in SolidWorks, finding the maximum width at thedistal radius when viewed from the volar perspective.

A distal radius plate designed in accordance with the method of theinvention is shown at 10 in FIGS. 1-5. The plate includes a surface 12which faces, and may at least partially be in contact with, the bonesurface. The plate also includes a surface 13 that faces outward fromthe bone surface. A distal portion 14 of the plate 10 is intended tosupport the distal most portion of the radius bone. The distal portionincludes a side 16 that supports the radial styloid and an opposite side18. In addition, the plate includes a proximal plate-like portion 20that spirals along the long axis of the radial bone as can be seen inparticular in FIGS. 3 through 5. In addition, the distal portionincludes holes 21 for pegs or screws 22, which support the distalportion of the radius. These holes can be threaded for locking screws,or can be free from threads or a locking mechanism. They can alsoincorporate a variable locking mechanism as is known in the art. Theplate portion also includes holes for fixation means, including forexample, screws and k-wires. The plate may include other features as arefound to be advantageous, such as the sliding slot 24 shown in theproximal portion of the plate.

FIG. 6( a) illustrates a cadaveric sample of a distal radius, and FIG.6( b) illustrates a corresponding 3D model for that bone sample. FIGS.7( a) through 7(e) illustrate the development of graphical models forindividual bone samples and FIGS. 8( a) through 8(e) illustrates theviews of the graphical models of the volar surfaces. FIGS. 9( a) and9(b) illustrate the alignments of the bones at the center of mass toallow a composite model to be assembled. FIG. 10( a) illustrates thecomposite graphical model with the bones of one of the small, medium orlarge category aligned at the centers of mass. FIG. 10( b) shows alofted plate sections that have been assembled into a shape to simulatea first plate design. FIGS. 11( a) and 11(b) illustrate the addition ofboth screws and instruments (in this case a drill guide) to theconstruct. FIG. 11( a) illustrates the design with the screws from thetop, and FIG. 11( b) illustrates a view from the medial side of theradius. This view further shows the placement and angles of the pegmembers which are used to fix fragments of the distal portion of theradius. FIGS. 12( a) through 12(c) illustrate a second design of theplate with loading at the center of mass axis of the radius bone andequally distributed at the surface of the plate. In FIG. 12( b), theload is applied at a 30° angle to the longitudinal axis. The load isapplied along the Y axis in FIG. 12( c). FIG. 13( a) shows a furtheriteration of the plate design with enlarged holes for a variable lockingmechanism. The placement, angles and length of bone screws and pegs areshown in FIG. 13( b) which has been tested using FEA analysis todetermine stress and deflection profiles.

While in accordance with the patent statutes the best mode and preferredembodiment have been set forth, the scope of the invention is notlimited thereto, but rather by the scope of the attached claims.

1. A method of designing an orthopedic implant for a bone comprising thesteps of selecting a plurality of samples of the bone and taking a CTscan of each of the samples of the bone; using the output from the CTscan to generate a 3D graphical solid body model of each of the sampleof the bone; placing the 3D graphical models into a category of one ormore of average, small, and large, determining the center of mass foreach 3D graphical model, and generating an X, Y and Z plane for eachmodel; placing the 3D graphical models for one category into an assemblyand aligning each the 3D graphical models in that category at the centerof mass to create a categorized composite 3D graphical solid body modelof the bone; forming a plurality of cross sections of the categorizedcomposite 3D graphical model and building cross sections of sections aplate which are assembled to create a lofted contoured surface andcutting the lofted contoured surface to create a categorized implantform; fitting the categorized implant form on the categorized composite3D graphical model and on the 3D graphical model of each of the sampleof the bone in a category to check for conformity to the surface of thebone; and using the categorized implant form to create a design of theimplant.
 2. A method as set forth in claim 1 further including the stepof creating a drawing of the categorized composite 3D graphical modelfor use to determine one or more of the size or the profile of theimplant;
 3. A method as set forth in claim 1 wherein the implant furtherincludes fixation holes and the method further includes the step ofusing data of common fractures of the bone and of the need for fixationand reduction to determine the location and angles of the fixation holesin the implant.
 4. A method as set forth in claim 2 wherein the methodfurther includes the step of creating a physical model of the bone usingthe categorized composite 3D graphical model.
 5. A method as set forthin claim 4 wherein the physical model of the bone comprises plastic andis created using a 3D plastic plotter.
 6. A method as set forth in claim1 wherein the method further includes the step of creating a physicalmodel of the implant using the categorized implant profile.
 7. A methodas set forth in claim 1 wherein a physical model is created for each ofthe samples of the bone in a category.
 8. A method as set forth in claim6 wherein the physical model of the implant comprises plastic and iscreated using a sterolithography.
 9. A method as set forth in claim 8further including the step of creating a physical model of the implantusing the categorized implant profile and wherein the physical model ofthe implant is fit on the physical model for each of the samples of thebone in a category.
 10. A method as set forth in claim 9 furtherincluding the step of adjusting the design of the implant based on theresults of the fit of the physical model of the implant on the physicalmodel of one or more of the categorized composite 3D graphical model oron the physical model of one of the samples of the bone in a category.11. A method as set forth in claim 10 wherein the adjustment to thedesign includes a change in the contour of the implant.
 12. A method asset forth in claim 10 wherein the adjustment to the design includes achange in the profile of the implant.
 13. A method as set forth in claim10 wherein the implant includes fixation holes and the adjustment to thedesign includes a change in the placement of the fixations holes.
 14. Amethod as set forth in claim 10 wherein the implant includes fixationholes and the adjustment to the design includes a change in the angle ofthe fixations holes.
 15. A method as set forth in claim 1 wherein thecategorized composite 3D graphical model is used for a finite elementanalysis.
 16. A method as set forth in claim 1 wherein the physicalmodel of the bone is used for a finite element analysis.
 17. A method asset forth in claim 15 wherein the categorized composite 3D graphicalmodel is modified to simulate a fracture of the bone, and a categorized3D graphical model of the implant is made and incorporated onto thecategorized composite 3D graphical model to create a 3D graphicalconstruct of a fractured bone with an implant and the 3D graphicalconstruct is subjected to loads.
 18. A method as set forth in claim 17wherein the loads are applied in directions and magnitudes to simulatenormal human activity and the stress and displacement of the implant ismonitored to generate information for optimization of the implant.
 19. Amethod as set forth in claim 18 wherein the information generated fromthe applied loads is used to optimize the design of the implant.
 20. Amethod of designing an orthopedic plate for a bone comprising the stepsof selecting a sample of the bone and taking a digital imaging scan ofthe sample of the bone; using the output from the digital imaging scanto generate a 3D graphical solid body model of the sample of the bone;sectioning the composite 3D graphical solid model to create a loftedcontoured surface of a selected thickness and using the lofted contouredsurface to create a graphical plate profile; and using the graphicalplate profile to create a design of the orthopedic plate.
 22. A methodas set forth in claim 20 further including the step of creating adrawing of the composite 3D graphical model for use to determine one ormore of the size or the shape of the orthopedic plate.
 23. A method asset forth in claim 20 wherein the orthopedic plate further includesfixation holes and the method further includes the step of using data ofcommon fractures of the bone to determine the location and angles of thefixation holes in the plate.
 24. A method as set forth in claim 20wherein the method further includes the step of creating a physicalmodel of the bone using the composite 3D graphical model.
 25. A methodas set forth in claim 24 wherein the physical model of the bonecomprises plastic and is created using a 3D plastic plotter.
 26. Amethod as set forth in claim 20 wherein the method further includes thestep of creating a prototype model of the plate using the graphicalplate profile.
 27. A method as set forth in claim 20 wherein a pluralityof samples of bone are selected for a defined category and a digitalimaging scan is taken for each sample, and a 3D graphical solid bodymodel is generated for each sample which are assembled to create acomposite 3D graphical model of the samples and further wherein aphysical model is created for each of the samples of the bone.
 28. Amethod as set forth in claim 26 wherein the prototype model of the plateis created using a sterolithography.
 29. A method as set forth in claim27 further including the step of creating a physical model of the plateusing the graphical plate profile and wherein the physical model of theplate is fit on the physical model for each of the samples of the bonein a defined category.
 30. A method as set forth in claim 29 furtherincluding the step of providing a graphical or physical model of theplate and of the bone to a surgeon and further adjusting the design ofthe plate based on the results of the fit of the physical model of theplate on the physical model of one or more of the composite 3D graphicalmodel or on the physical model of one of the samples of the bone in adefined category.
 31. A method as set forth in claim 30 wherein theadjustment to the design of the plate includes a change in the contourof the implant.
 32. A method as set forth in claim 30 wherein theadjustment to the design of the plate includes a change in the profileof the implant.
 33. A method as set forth in claim 30 wherein the plateincludes fixation holes which accept screws or pegs and the adjustmentto the design includes a change in the placement of the fixations holes.34. A method as set forth in claim 30 wherein the plate includesfixation holes which accept screws or pegs and the adjustment to thedesign includes a change in the angle of the fixations holes.
 35. Amethod as set forth in claim 20 wherein the composite 3D graphical modelis used for a finite element analysis.
 36. A method as set forth inclaim 20 wherein a physical model of the bone is created from artificialbone.
 37. A method as set forth in claim 35 wherein the composite 3Dgraphical model is modified to simulate a fracture of the bone, and a 3Dgraphical model of the plate is made and incorporated onto the modifiedcomposite 3D graphical model of the bone to create a 3D graphicalconstruct of a fractured bone with the plate and the 3D graphicalconstruct is subjected to loads.
 38. A method as set forth in claim 37wherein the loads are applied in directions and magnitudes to simulatenormal human activity and the stress and displacement of the plate ismonitored to generate information for optimization of the design of theplate.
 39. A method as set forth in claim 38 wherein the informationgenerated from the applied loads is used to optimize the design of theplate.
 40. A method as set forth in claim 20 wherein the bone is aradius.
 41. The product made from the design of the orthopedic plate ofclaim
 20. 42. A method of designing a plate for a one or more of a smallbone comprising the steps of selecting a plurality of samples of thesmall bone and taking a digital imaging scan of each of the samples ofthe small bone and using the output from the digital imaging scan togenerate a 3D graphical solid body model of each of the samples of thesmall bone; determining the center of mass for each 3D graphical model,and generating an X, Y and Z plane for each model and aligning each the3D graphical models at the center of mass corresponding to the X, Y, andZ planes to create a composite 3D graphical solid body model of thesmall bone; using the composite 3D graphical model to create a graphicalsmall bone plate profile; graphically fitting the graphical small boneplate profile on the composite 3D graphical model and on the 3Dgraphical model of each of the sample of the small bone in a category tocheck for conformity of the small bone plate profile to the surface ofthe small bone; and using the graphical small bone plate profile tocreate a design of the small bone plate.
 43. A method as set forth inclaim 42 further including the step of sorting the 3D graphical modelsinto the categories of small, average and large.
 44. A method as setforth in claim 42 wherein the small bone plate further includes fixationholes and the method further includes the step of using data of commonfractures of the small bone to determine the location and angles of thefixation holes in the small bone plate.
 45. A method as set forth inclaim 46 wherein the method further includes the step of creating aphysical model of the small bone using the composite 3D graphical model.46. A method as set forth in claim 45 wherein the physical model of thesmall bone comprises resin, plastic or artificial bone.
 47. A method asset forth in claim 42 wherein the method further includes the step ofcreating a prototype model of the small bone plate using the small boneplate profile.
 48. A method as set forth in claim 42 wherein a physicalmodel is created for each of the samples of the small bone.
 49. A methodas set forth in claim 47 wherein the design of the small bone plate iscreated in a right and a left version.
 50. A method as set forth inclaim 48 further including the step of creating a physical model of thesmall bone plate using the graphical small bone plate profile andwherein the physical model of the small bone plate is fit on a pluralityof physical models of the small bone.
 51. A method as set forth in claim50 further including the step of adjusting the design of the small boneplate based on the results of the fit of the physical model of the smallbone plate on the physical model of one or more of the composite 3Dgraphical model or on the physical model of one of the samples of thesmall bone.
 52. A method as set forth in claim 42 wherein the adjustmentto the design of the small bone plate includes a change in the contouror the profile of the small bone plate.
 53. A method as set forth inclaim 42 wherein the small bone plate includes fixation holes whichaccept screws or pegs, and the adjustment to the design includes achange in the placement or the angle of the fixations holes.
 54. Adistal radius plate made in accordance with the method set forth inclaim
 42. 55. A calcaneal plate made in accordance with the method setforth in claim 42.